Apparatus and process for preparing pulverous iron ores and the like for smelting in blast-furnaces and use in open-hearth furnaces.



S. CORNELL.

APPARATUS AND PROCESS POR PREPARING PULVEROUS IRON GRES AND THE LIKE POR SMBLTING IN BLAST PURNACBS AND USE IN OPEN HEARTH PURNAGES.

APPLIUATION FILED PEB. 9, 1909. 962,006, Patented June 21,1910 Y zsHBBT HEBT 1. 4 v N 7 S. CORNELL. APPARATUS AND PROCESS POR PREPARI'NGIPULVEROUS IRON @RES AND THE LIKE POR SMELTING IN BLAST FURNAGES vANI) USE IN OPEN HEARTH FUBNACBS.

APPLIGATION FILED 1EBB. 9. 1909. s Patented June 21, 1'910.

2 SHEETS-SHEET 2.

are c?.-

v INI/ENTR.

SIDNEY CORNELL, or nUeUEsNE, PnnnsYLvANIA.

APPARATUS AND PROCESS FOR PREPARING PULVEROUS IRON ORES AND THE LIKE FOR SMELTING- IN BLAST-FURNA'CES AND USE IN OPEN-HEARTH FURNACES.

specification of Letters Patent.

Patented J une 21, 1910.

Application led February 9, '1909. Serial N o. 476,891.'

To all whom it may concern:

Be it known that I, SIDNEY CORNELL, a

. citizen of the UnitedStates, residing at of which the following is a specification.

My invention relates to means f or sintering and otherwise preparing pulverous iron ores, flue dust, magnetic concentrates, and other materials of similar nature for smelting in blast furnaces and use in open hearth furnaces used in the manufacture of iron and steel. Such materials being naturally in a state of too fine division or composed of too small particles to be retained in those furnaces while subjected to blast in smelting, resort has been had to sintering and briqueting them into workable conditions.

Pulverous iron ores, fine-dust, or magnetic concentrates may, without admixture with other material, be sintered or clinkered by heating them to a temperature slightly above 2500 degrees Fahrenheit, such action being caused by the melting of a part of the material so heated, and. said fused portion acting as a binder 'for the unfused residue of material. This action is probably due to the formation of ferrous silicateswhich constitute the binder of the residue of the material remaining unsintered, the sintering process, thus makin its reduction more diticult and costly, an it is, therefore, desirable that it be returned to the ferrie condition by subjecting the clinker while heated to oxidation in order to its being more easily smelted if used in a blast furnace, and becoming a more etlicient material in open hearth furnaces because of the larger content of oxygen in lthe oxidized clinker, than in the unoxid'ized clinker.

My invention has for its object a single simple apparatus, and a continuous process for sintering these pulverous materials, restoring .them to the ferrie condition, and delivering them in masses of convenient size for hand 111g' and working.

My apparatus isshown in the accompanying drawin forming a part of this specification, an in whic Figure 1 is a vertical 1:0 'tudinal midsection view of me construction; Fig, 2 is 'rotate the same.

a vertical cross-sectionl view thereof taken on the line 2 2 in Fig. '1; and Fig. 3 is a perspective view thereof showing the walls of the apparatus partially broken away to disclose the interior arrangements. 6 The outer wall, 1, of the furnace is arched throughout its length, as shown. Within said outer wall, and spaced therefrom to form an intermediate chamber, is a second arched or curved wall, 2, 21, which is broken 6 at its crown by the `longitudinal pit, 3. The walls l, 2, 21, are constructed of suitable refractory material to withstand high heat.

4, 4 are gas ducts'bordering each side of the outer wall, 5v'1, throughout its length, or 7 nearly so; L)and opening from said ducts through said outer wall into the chamber 5, are the tubes or burners 6, 6. Apertures 7, 7 are jformedin'the crown of the outer wall A1, which opens into a smoke-box 8, con- 7 necting at its end with the stack 9, and opening intoA it; said arrangements being provided to enable the escape from the lchamber 5 of the products of combustion. Below the chamber 5 are inclinedl tables or surfaces, 8

10, 11, arranged to receive from the chamber 5 the partially treated materials. Near the bottom of the pit, 3, and throughout its length lies a screw conveyer, l2, which is actuatedA through the gear, 13, or by any equivalent means for conveying vpower to At the outer. end of said. screw is placed the hopper 14. The screw conveyer, l2, in that part of its structure lnear the outer' end thereof has the pitch of 9 its blade formed at an angle in which .the conveying principle predominates, while the Lremainder and greater part of the blade is pitched at an angle in which the lifting f principle predominates. '9 The operation of my construction and the consequent process are as follows The ma terial t'o be treated is fed into the hopper, 14, and is forced into the pit, 3, by the conveyer, 12, which is rotated by power applied l to the gear, 13. The material is continuously forced into the pit until the pit is filled from end to end und the material is forced above the upper edges of the pit and passes out and over upon the' upper faces 1 of, the curved walls 2, 21. The gas passing through the ducts, 4, 1, and burners 6, 6, being ignited at the inner ends of thehburners, heats the inside of the arched well, 1, to a high degree, and the mass of l material being treated is heated directly and .by the heat reiected from said arched wall.

Y pieces of the crust, and exposing to the direct action of the heat the raw or unsin tered side thereof, so that it becomes-sintered on all sides. As the feeding process continues the broken clinker piles up upon the curved Walls, 2, 21, beyond the angle of repose (indicated by the dotted line lvin Fig. 2), and then rolls down upon the tables 10, 11. When it reaches these tables the material consists of conglomerated iron oXids, but a large portion of which is in ferrous or deoxidizedcondition. On these tables the broken clinker remains sufficiently long for the air passing from below, through and over it into the chamber, 5, to oxidize the ferrous oxid of the clinker into ferrie condition, whereby the material becomes properly prepared and workable in the smelting furnace. When the clinker has laid long enough upon the tables to become suiiciently cool it is dumped into the car, 17, below. The air passing over the clinker on the inclined tables, cools the clinker, and is at the same `time highly heated thereby, and while aiding the combustion of the gas passing .from the burners also aids in the production of a higher temperature within the furnace. rlhe Awavy motion given the mass of material iii the pit, 3, by the screw conveyer not only causes the breaking up of the crust or clinker formed upon the top of the pile of material, but also loosens and agitates the material beneath the crust, thereby allowing any gases generated in the massief material in the pit to escape through the breaks or rifts in the crust, while, in

- the treatment of flue dust it permits the elimination of the coke in the dust by the burning out of this carbon, the products of combustion passing olf through Athe smoke box and stack. The rate of clinkerinv can be controlled through the motion of the screw, and by regulating thespeed of its rotation, the maximum amount of material can be run through the apparatusconsistent with proper treatment.

By the described apparatus and process I procure the formation of the pulverous materials treated in masses of size and weight available for smelting in blast furn'aces' and use in open hearth furnaces, and restore the Y deoxidized parts thereof to the ferrie condition by a single continuous operation economically, rapidly and effectively conducted.

land said receptacle,

means for producing iiame in said chamber;

means for conveying material to be treated into said chamber, fracturing the sintered portion thereof when formed, and discharging Vit from said chamber, and means whereby said sintered product is arrested and exposed to the air while hot.

3. In apparatus for sintering pulverous iron ores and the like, a heating chamber; means for producing flame in said chamber; means for conveying material to be treated into said chamber, exposing it in bulk to the heat therein, fraeturing the sintered crust thereon when formed, and discharging said sintered crust from said'cham'ber, and means'for arresting and detaining said sintered product while hot to a current of air directed to said heating chamber.

4:. The process of agglomerating pulverous iron ores and the like, which consists 'in subjecting the treated material in bulk to a high heat; converting the surface of the and fracturing said crust.

5. The process of treating pulverous iron ores and the like, which consists in subjecting the treated material in bulk to a high heat; converting the surface of the material exposed to such heat into a crust, and fracturing such crust and exposing it to the air while hot.

6. In apparatus for preparing pulverous iron ores and the like for smeltlng in blast furnaces or use'in open hearth furnaces, the

.material exposed t0 such heat into a crust combination of a heating chamber having an inclined floor; a channel opening to said floor; a screw conveyer lying within said channel and having a blade or blades of varied pitch, the pitch of saidA blade or blades in the forward part of said conveyer having a pitch in which the conveying principle predominates,'and the remainder orv greater part of said blade or bladesfhaving a pitch in which the lifting. principle vpredominates; a receptacle located, in a lower plane than said inclined floor "and adjacent thereto, apassage between said inclined floor leading from the outer air to the interior of said heating chamber; means for operating said conveyer, and means for heating the interior of said chamber.

7. In apparatus for preparing pulverous iron ores and the like for smeltmg in blast furnaces or use in open hearth furnaces, the

combination of a heating chamber having an arched roof and an inclined floor, a chan-A nel in said floor and a screw oonveyer lying within said channel; a table located below the level of the oor of said chamber and at one side thereof; a passage over said table and openin into said heating chamber, and means for heating the interior of said chamber.

8. In apparatus for reparing pulverous iron ores and the like ,or smelting in blast furnaces or use in open hearth furnaces, the

combination of a heating chamber, having an arched roof and arched floor; a channel opening through said floor; a screw conveyer lying within said channel and having a blade or blades of varied pitch, whereby said conveyer is adapted for conveying and liftin the material in which it rotates; a plura ity of tables located below the level of the floor of said chamber and at the sides thereof; passages opening from said chamber and continuing past said tables; `and means for the escape from said chamber of the products of combustion.

9. The process of reparingpulverous iron ores and the like or smelting in blast furnaces, or use in open hearth furnaces, consisting in first subjecting the material to a high heat and converting it into a conglomerated mass through the reduction of the ore as it exists in the ferrie oxid form into the ferrous-ferrie oxid form, and then by reoxidizing the mass or converting it from the ferrous-ferrie oxid, form into the ferrie form.

10. The process ofv reparing pulverous iron ores and the like or smelting in blast furnaces, .or use in open hearth furnaces,

consisting in rst sinte'ring the material, converting the iron oxids contained therein into a ferrous-ferrie condition,'an'd then restoring the resulting ferrous-ferrie oxids to a ferrie condition by exposing the treated material while hot to a current of air.

11. The process of preparing pulverousv iron ores and the like for sinelting in blast furnaces or use in open hearth furnaces, said process consisting in iirst continuously' feeding the material to be treated into a heating chamber, sintering the exposed surface of the mass of material, heaving the accumulating mass of material, breaking its sintered crust and exposing its unsintered portions to the heat in said chamber until sintered, and then exposing the broken crust whilehot to a current of air bringing it to a ferrie condition.

12. The process of reparingv pulverous iron ores and the like or smeltlng in blast furnaces or use in open hearth furnaces, consisting in continuously feeding the material to be treated into a heating chamber, and exposing the surface of the mass of material to a suiiicient heat to form thereon a sintered crust, heaving the mass of material sufliciently to break its sintered crust and turn the same so as to expose its unsintered parts to the reflected heat in said chamber, and then depositing the sintered material at a point where it 1s exposed to a current of air passing into said heating chamber whereby said material may be simultaneously cooled and restored to a ferrie condition.

. SIDNEY CORNELL.

Witnesses W. E. REED, H. L. BLAcK. 

